Line of sight (LoS) communication systems are useful for various situations. For example, many cellular telephones communicate via LoS in radio frequency bands. Furthermore, LoS systems may allow for communication to occur after a disaster has struck and other means of communication are unavailable.
It is desirable for LoS (and other communication means) to have a relatively large bandwidth. The conventional approach to increasing bandwidth uses multiple spatially separated transmitter antennas. In such a system, each data-carrying beam is received with multiple spatially separated receivers, and signal processing is used to recover the different data streams. This processing reduces the crosstalk that appears from one beam into the receiver antenna intended for its spatially separated neighboring channel. However, such technology is relatively expensive to implement and the costs increase as the quantity of transmitters and receivers increase.